A photocatalyst powder is provided. The photocatalyst powder includes a plurality of nano crystallite aggregates formed by a plurality of nano crystallites. Each of the nano crystallites exhibits a single crystal structure. The nano crystallites have different compositions, different crystal phases, and different lattice constants from each other. An example of the nano crystallites is represented as the formula of ZnO.sub.1-xS.sub.x with different x values in each of the nano crystallites. In addition, a hydrogen producing system is also provided.

A bimetal oxysulfide solid-solution catalyst is provided. The bimetal oxysulfide solid-solution catalyst is represented by the following formula:
Cu.sub.xM.sup.(2).sub.yO.sub.zS.sub.γ wherein M.sup.(2) includes monovalent Silver (Ag), divalent Zinc (Zn), Manganese (Mn), Nickel (Ni), Cobalt (Co), and Tin (Sn.sup.II), trivalent Indium (In), Cerium (Ce), Antimony (Sb), and Gallium (Ga), tetravalent Tin (Sn.sup.IV), or pentavalent Molybdenum (Mo), 0<y<0.3, 0.7<x<1.0, 0<z<0.5, and 0.5<γ<1.0. In addition, a manufacturing method of the bimetal oxysulfide solid-solution catalyst and applications of the bimetal oxysulfide solid-solution catalyst are also provided.

The invention describes a process for the photocatalytic reduction of carbon dioxide carried out in the liquid phase and/or in the gas phase under irradiation employing a photocatalyst of microporous crystalline metal sulfide type, said process being carried out by bringing a charge containing the CO.sub.2 and at least one sacrificial compound into contact with said photocatalyst, then by irradiating the photocatalyst by at least one irradiation source producing at least one wavelength lower than the bandgap width of said photocatalyst, so as to reduce the CO.sub.2 and to oxidize the sacrificial compound, so as to produce an effluent containing, at least in part, C.sub.1 or more carbon-based molecules other than CO.sub.2.

The invention describes a process for the photocatalytic reduction of carbon dioxide carried out in the liquid phase and/or in the gas phase under irradiation employing a photocatalyst of microporous crystalline metal sulfide type, said process being carried out by bringing a charge containing the CO.sub.2 and at least one sacrificial compound into contact with said photocatalyst, then by irradiating the photocatalyst by at least one irradiation source producing at least one wavelength lower than the bandgap width of said photocatalyst, so as to reduce the CO.sub.2 and to oxidize the sacrificial compound, so as to produce an effluent containing, at least in part, C.sub.1 or more carbon-based molecules other than CO.sub.2.

Methods, reactor tubes, reactors, and systems for catalysis are disclosed. A reactor tube includes an outer shell defining a catalyst bed, a catalyst within the catalyst bed, and an inner tube extending through the catalyst bed. An interior of the inner tube is isolated from the catalyst within the catalyst bed. Methods of activating a catalyst are also disclosed herein.

A method of synthesizing a doped carbonaceous material includes mixing a carbon precursor material with at least one dopant to form a homogeneous/heterogeneous mixture; and subjecting the mixture to pyrolysis in an inert atmosphere to obtain the doped carbonaceous material. A method of purifying water includes providing an amount of the doped carbonaceous material in the water as a photocatalyst; and illuminating the water containing the doped carbonaceous material with visible light such that under visible light illumination, the doped carbonaceous material generates excitons (electron-hole pairs) and has high electron affinity, which react with oxygen and water adsorbed on its surface forming reactive oxygen species (ROS), such as hydroxyl radicals and superoxide radicals, singlet oxygen, hydrogen peroxide, that, in turn, decompose pollutants and micropollutants.

A method of synthesizing a doped carbonaceous material includes mixing a carbon precursor material with at least one dopant to form a homogeneous/heterogeneous mixture; and subjecting the mixture to pyrolysis in an inert atmosphere to obtain the doped carbonaceous material. A method of purifying water includes providing an amount of the doped carbonaceous material in the water as a photocatalyst; and illuminating the water containing the doped carbonaceous material with visible light such that under visible light illumination, the doped carbonaceous material generates excitons (electron-hole pairs) and has high electron affinity, which react with oxygen and water adsorbed on its surface forming reactive oxygen species (ROS), such as hydroxyl radicals and superoxide radicals, singlet oxygen, hydrogen peroxide, that, in turn, decompose pollutants and micropollutants.

The disclosure relates to a method for making a photocatalytic structure, the method comprising: providing a carbon nanotube structure comprising a plurality of carbon nanotubes intersected with each other; a plurality of openings being defined by the plurality of carbon nanotubes; forming a photocatalytic active layer on the surface of the carbon nanotube structure; applying a metal layer pre-form on the surface of the photocatalytic active layer; and annealing the metal layer pre-form.

The disclosure relates to a method for making a photocatalytic structure, the method comprising: providing a carbon nanotube structure comprising a plurality of carbon nanotubes intersected with each other; a plurality of openings being defined by the plurality of carbon nanotubes; forming a photocatalytic active layer on the surface of the carbon nanotube structure; applying a metal layer pre-form on the surface of the photocatalytic active layer; and annealing the metal layer pre-form.

The present invention relates to a method for dissolving metals by photocatalysis. A metal-containing material to be dissolved is dispersed in a mixed solution of photocatalyst-containing cyanide and organic chloride; then, a photocatalyst is added; next, an oxygen-containing gas or a substance which is capable of generating oxygen is introduced; and irradiation is applied for a period of time to dissolve metals. Compared with the prior method, the present invention is advantageous in moderate reaction condition, energy conservation, environmental protection, low cost, and convenient operation, and is suitable for mass industrial treatment on metal dissolution.